Heat's impact on crops won't show until season's end

MILLERSBURG -- Temperatures in the upper 80s and 90s for the past few weeks have certainly been tiresome for farmers working in the fields but area corn crops really seem to love it.

"I know over the last week, corn has really kicked it into high gear as far as growth goes," said Ron Becker, OSU Extension Agricultural and Natural Resources program coordinator. "I've heard people talking about some of their corn growing from 48 inches to 60 inches in a week's time. That's nearly 2 inches a day."

The benefit corn is seeing from the heat might go beyond just growth as Becker also reported that there haven't been many reports of any of the diseases farmers might typically begin to see around this time such as gray leaf spot or northern corn leaf blight.

"These diseases like it better around the same temperature we do," Becker said. "Normally we see these, especially in the no-till fields, but this year we haven't. It doesn't mean that we won't but maybe the hot air is too much for it."

A few months ago, many people were worried about the wet weather and being so late at getting the corn planted but Becker looks back at that now as a possible blessing.

Normally by this time, the corn is into its silking stage but since most fields were planted so late, they are not to that point yet. If the plant were undergoing such extreme conditions during silking, the heat could have had a more significant impact.

As much as a benefit as the heat has been so far for the corn, if it continues, it could begin to be a significant problem. If the plants are unable to get enough moisture through their root system, the leaves might begin to curl up, which could decrease the overall yield.

"If this continues for another week or 10 days it could become a problem," Becker said. "You can have a couple of days where it gets up to 104-105 and it's no problem, but when it's continually being stressed, that's when you're going to have issues."

Another fact that could come into play is how developed of a root system the plants have to work with. During the wet spring, the roots did not have to grow very far to get the necessary water for the plants to grow. Now that the soil is drying and heating up, the plant might not have an elaborate enough root system to thrive.

While the corn has benefited from the heat, cole crops such as cabbage, broccoli and cauliflower have not weathered so well. The heat keeps the plants from causing a head and producing a seed stalk earlier.

"Spinach or lettuce, when they go to seed, they put up a seed stalk that produces the seeds for next year and that either makes the leaves that we want to consume bitter or quits producing them altogether," Becker said. "Those plants are under stress so they say 'the purpose of my life is to produce more seeds for next year and even though I want to make more leaves, I can't."

Becker also issues a warning to farmers who are still applying herbicides during the extreme heat. Rather than being absorbed into the ground where it is applied, the heat makes the herbicides evaporate into the air and can be spread around with no control.

The impact this heat wave will have on local crops likely won't be measured until the end of the season. With an already shortened season from the rain, Becker is hoping that a late frost will come with it.

"If I had a crystal ball I could tell you (the impact) but it depends a lot on how long it lasts and how late of a frost we get," Becker said.

Reporter Jeff Canning can be reached at 330-674-5676 or jcanning@the-daily-record.com.